SciCADE 95: International conference on scientific computation and differential equations

This report consists of abstracts from the conference. Topics include algorithms, computer codes, and numerical solutions for differential equations. Linear and nonlinear as well as boundary-value and initial-value problems are covered. Various applications of these problems are also included

NASA Tech Briefs, May 2013

Topics include: Test Waveform Applications for JPL STRS Operating Environment; Pneumatic Proboscis Heat-Flow Probe; Method to Measure Total Noise Temperature of a Wireless Receiver During Operation; Cursor Control Device Test Battery; Functional Near-Infrared Spectroscopy Signals Measure Neuronal Activity in the Cortex; ESD Test Apparatus for Soldering Irons; FPGA-Based X-Ray Detection and Measurement for an X-Ray Polarimeter; Sequential Probability Ratio Test for Spacecraft Collision Avoidance Maneuver Decisions; Silicon/Carbon Nanotube Photocathode for Splitting Water; Advanced Materials and Fabrication Techniques for the Orion Attitude Control Motor; Flight Hardware Packaging Design for Stringent EMC Radiated Emission Requirements; RF Reference Switch for Spaceflight Radiometer Calibration; An Offload NIC for NASA, NLR, and Grid Computing; Multi-Scale CNT-Based Reinforcing Polymer Matrix Composites for Lightweight Structures; Ceramic Adhesive and Methods for On-Orbit Repair of Re-Entry Vehicles; Self-Healing Nanocomposites for Reusable Composite Cryotanks; Pt-Ni and Pt-Co Catalyst Synthesis Route for Fuel Cell Applications; Aerogel-Based Multilayer Insulation with Micrometeoroid Protection; Manufacturing of Nanocomposite Carbon Fibers and Composite Cylinders; Optimized Radiator Geometries for Hot Lunar Thermal Environments; A Mission Concept: Re-Entry Hopper-Aero-Space-Craft System on-Mars (REARM-Mars); New Class of Flow Batteries for Terrestrial and Aerospace Energy Storage Applications; Reliability of CCGA 1152 and CCGA 1272 Interconnect Packages for Extreme Thermal Environments; Using a Blender to Assess the Microbial Density of Encapsulated Organisms; Mixed Integer Programming and Heuristic Scheduling for Space Communication; Video Altimeter and Obstruction Detector for an Aircraft; Control Software for Piezo Stepping Actuators; Galactic Cosmic Ray Event-Based Risk Model (GERM) Code; Sasquatch Footprint Tool; and Multi-User Space Link Extension (SLE) System

Integrated Chemical Processes in Liquid Multiphase Systems

The essential principles of green chemistry are the use of renewable raw materials, highly efficient catalysts and green solvents linked with energy efficiency and process optimization in real-time. Experts from different fields show, how to examine all levels from the molecular elementary steps up to the design and operation of an entire plant for developing novel and efficient production processes

Graduate Division Programs for the Academic Year 1976-77 New Jersey Institute of Technology

https://digitalcommons.njit.edu/coursecatalogs/1018/thumbnail.jp

Real-Time Optimization for Estimation and Control: Application to Waste Heat Recovery for Heavy Duty Trucks

This thesis aims at the investigation and development of the control of waste heat recovery systems (WHR) for heavy duty trucks based on the organic Rankine cycle. It is desired to control these systems in real time so that they recover as much energy as possible, but this is no trivial task since their highly nonlinear dynamics are strongly affected by external inputs (disturbances). Additionally, nonlinear operational constraints must be satisfied. To deal with this problem, in this thesis a dynamic model of a WHR that is based on first principles and empirical relationships from thermodynamics and heat transfer is formulated. This model corresponds to a DAE of index 1. In view of the requirements of the employed numerical methods, it includes a spline-based evaluation method for the thermophysical properties needed to evaluate the model. Therewith, the continuous differentiability of the state trajectories with respect to controls and states on its domain of evaluation is achieved. Next, an optimal control problem (OCP) for a fixed time horizon is formulated. From the OCP, a nonlinear model-predictive control (NMPC) scheme is formulated as well. Since NMPC corresponds to a state feedback strategy, a state estimator is also formulated in the form of a moving horizon estimation (MHE) scheme. In this thesis, we make use of efficient numerical methods based on the direct multiple shooting (DMS) method for optimal control, backward differentiation formulae for the solution of initial value problems for DAE, and the corresponding versions of the real-time iteration (RTI) scheme in order to approximately solve the OCP and implement the MHE and NMPC schemes. The simultaneous implementation of NMPC and MHE schemes based on RTI has been already proven to be stable in the control literature. Several numerical instances of the DMS method for the proposed OCP, NMPC and MHE schemes are tested assuming a given real-world operation scenario consisting of truck exhaust gas data recorded during a real trip. These data have been kindly provided by our industry cooperation partner Daimler AG. Additionally, the PI and LQGI control strategies, of wide-spread use in the literature of control of WHR, are also considered for comparison with the proposed scheme. An important result of this thesis is that, considering the highest energy recovery obtained from both strategies as a reference for the given operation scenario, the proposed NMPC scheme is able to reach an additional energy generation of around 3% when the full state vector is assumed to be known, and its computational speed allows it to update the control function in times shorter than the considered sampling time of 100 [ms], which makes it a suitable candidate for real-time implementation. In a more realistic scenario in which the state has to be estimated from noisy measurements, a combination of both aforementioned NMPC and MHE schemes yields an additional energy generation of around 2%. Concretely, this thesis presents novel results and advances in the following areas: • A first principles DAE model of the WHR is presented. The model is derived from the energy and mass conservation considerations and empirical heat transfer relationships; and features a tailored evaluation method of thermophysical properties with which it possesses the property of being at least continuously differentiable with respect to its controls and states on its whole domain of evaluation. • A new real-time optimization control strategy for the WHR is developed. It consists of an NMPC strategy based on efficient simulation, optimization and control tools developed in previous works. The scheme is able to explicitly handle nonlinear constraints on controls and states. In contrast to other NMPC instances for the WHR found in the literature, our scheme's efficient numerical treatment make it real-time feasible even if the full nonlinear WHR dynamics are considered. • To the author's knowledge, this is the first implementation that considers both the NMPC and the MHE approaches used simultaneously in the control of the WHR. The combination of NMPC and MHE produces a closed-loop, model-based implementation that can treat realistic measurements as inputs and calculates the corresponding control functions as outputs

New Jersey Institute of Technology Catalog of Graduate Programs 1975-1976 Academic Year

https://digitalcommons.njit.edu/coursecatalogs/1020/thumbnail.jp

Ultraschnelle Photochemische Dynamik von Azobenzolen unter dem Einfluss Intra- und Intermolekularer Wechselwirkungen und von einem Protonentransfer-Schalter

The main goal of this Thesis was the investigation of the photochemical properties and ultrafast isomerization dynamics of several azobenzene (AB) derivatives under the influence of different intra- and intermolecular effects by means of femtosecond time-resolved absorption and fluorescence spectroscopy. The influence of electron donating and accepting substituents on the electronic relaxation was investigated for a push-pull AB. The dynamics of the push-pull AB and a bifunctional AB were also investigated with the chromophores covalently attached to tightly cross-linked polymer colloids. Due to the strong intermolecular mechanical forces acting on the photoexcited ABs, the excited state lifetimes in the polymeric were found to be dramatically longer compared to the lifetimes in solution. A systematic study on possible intramolecular interactions between chromophores was performed for two multi-azobenzene compounds. Transient absorption anisotropy decay measurements allowed to obtain insight into intramolecular chromophore-chromophore interactions on the time scale of several tens of femtoseconds. The data provide clear evidence for strong electronic coupling. The ultrafast dynamics of a magnetically bistable nickel porphyrin functionalized with an azopyridine as photoswitchable unit were investigated to obtain insight into the isomerization mechnanism and a possible switch of the spin state of the nickel ion. Furthermore a bistable excited state intramolecular proton transfer (ESIPT) switch was investigated. The data clearly suggest a stepwise formation of the desired proton transfer product via two intermediate states.Das Hauptziel dieser Arbeit lag in der Untersuchung der photochemischen Eigenschaften und der ultraschnellen Dynamik von Azobenzol (AB)-Derivaten unter dem Einfluss verschiedener intra- und intermolekularer Effekte mittels Femtosekunden-zeitaufgelöster Absorptions- und Fluoreszenzspektroskopie. Der Einfluss elektronenziehender und -schiebender Substituenten auf die elektronische Desaktivierung wurde für ein push-pull AB untersucht. Außerdem wurde die Dynamik des push-pull ABs und eines bifunktionalen ABs kovalent an stark vernetzte Polymerkolloide gebunden untersucht. Die starken intermolekularen Kräfte, die auf das AB wirken, führen zu einer deutlichen Verlängerung der Lebenszeiten des angeregten Zustands in den polymeren Mikronetzwerken im Vergleich zu den Lebenszeiten in Lösung. Mögliche intramolekulare Wechselwirkungen wurden in einer systematischen Studie an zwei Multi-Azobenzol Komponenten untersucht. Transiente Absorptionsanisotropiemessungen ermöglichten dabei einen Einblick in intramolekulare Chromophor-Chromophor-Wechselwirkungen auf der Femtosekunden- Zeitskala. Die erhaltenden Daten geben deutliche Hinweise auf starke elektronische Kopplung. Die ultraschnelle Dynamik eines magnetisch bistabilen Nickelporphyrins, das mit einem Azopyridin als photoschaltbarer Einheit funktionalisiert ist, wurde untersucht, um einen Einblick in den Isomerisierungsmechanismus und eine mögliche Änderung des Spinzustands zu erhalten. Außerdem wurde ein bistabiler Protonentransferschalters, der auf dem ESIPT (excited state intramolecular proton transfer)-Prinzip basiert, untersucht. Die Ergebnisse weisen deutlich auf die stufenweise Bildung des gewünschten Protonentransferprodukts über zwei Zwischenzustände hin